Systems and apparatuses include a circuit structured to receive information indicative of a catalyst health, receive information from a sensor array indicative of a catalyst activity, determine a catalyst health management criteria has been met based on the information, determine a catalyst age based on the information indicative of the catalyst activity and the catalyst health management criteria being met, compare the determined catalyst age to a predetermined age threshold, and provide a notification when the determined catalyst age exceeds the predetermined age threshold.

A method to reduce during the start of an engine undesired emissions from the engine, where an SCR catalytic converter for the cleaning of exhaust gases is arranged in an exhaust passage at the engine. The method includes controlling the dosage of fuel to the engine with a certain delay relative to what is the case during essentially optimal combustion in order to reduce the development of heat that results from the combustion of fuel through non-optimal combustion. Also a computer program product comprising program code to implement a method of reducing emissions. Also an arrangement to reduce during the start of an engine undesired emissions from the engine and a motor vehicle that is equipped with the arrangement.

Selective catalytic reaction (SCR) failure detection systems and methods for propulsion systems. The method includes obtaining (a) an upstream (of the SCR unit) NO.sub.x concentration value, and (b) a downstream NO.sub.x concentration value, and caching (a) and (b). The obtaining and caching is repeated until N cached values are obtained, where N is a preprogrammed number. Using the N cached values, an upstream average of NO.sub.x, an upstream standard deviation, a downstream average of NO.sub.x, and a downstream standard deviation are calculated. The calculated values are input for a failure detection algorithm pertaining to nitrogen oxides (NO.sub.x) that generates a linear correlation factor. A best performing unacceptable (BPU) part is detected when the linear correlation factor is greater than a preprogrammed fail threshold.

A method of manufacturing an on-board diagnostic (OBD) limit part and a method of testing to evaluate an OBD system. The method of manufacturing the OBD limit part includes introducing a contaminant to a selective catalytic reduction (SCR) catalyst and contacting the contaminant with the SCR catalyst for a selected period of time. The method of manufacturing utilizes a vessel, the contaminant, and the SCR catalyst. The OBD limit part is a combination of the contaminant and the SCR catalyst within the vessel. The method of testing to evaluate the OBD system includes collecting data related to an exhaust gas before and after the exhaust gas is exposed to the OBD limit part, collecting an indication provided by the OBD system, and comparing the data related to the exhaust gas and the indication provided by the OBD system. The method of testing to evaluate the OBD system utilizes a system that includes an exhaust gas source, a first and a second fluid path, the OBD limit part, and the OBD system.

According to various embodiments, an exhaust treatment system includes a catalyst that is in direct contact with an exhaust stream, at least one sensor that senses a system parameter and produces one or more signals corresponding to the system parameter, and a controller that is configured to receive the one or more signals and control catalyst performance based on the one or more signals by regenerating the catalyst. Regenerating the catalyst includes increasing a temperature of the exhaust stream flowing to the catalyst and directing a reductant injector to adjust a flow rate of reductant being injected into the exhaust stream flowing to the catalyst.

A method for controlling an exhaust gas aftertreatment system, wherein the system includes a first selective catalytic reduction (SCR) device, a catalytic particulate filter arrangement arranged downstream of the first SCR device, and a second selective catalytic reduction (SCR) device arranged downstream of the catalytic particulate filter arrangement. The method includes estimating future exhaust conditions based upon predicted vehicle operating conditions (s4103); —estimating a future NOx conversion demand based on the estimated future exhaust conditions (s405); —dosing a reducing agent from a first reducing agent dosing device at a rate based at least on the estimated future NOx conversion demand (s406).

An additive amount of a reducing agent to a selective reduction-type NOx catalyst is optimized. An ammonia adsorption amount of the selective reduction-type NOx catalyst is estimated based on one or a plurality of prescribed parameters related to the ammonia adsorption amount and a specific ammonia adsorption amount that is an estimated value of the ammonia adsorption amount specified by at least one of a maximum value and a minimum value of an estimated value of the ammonia adsorption amount is estimated based on an error in the prescribed parameter, and when the specific ammonia adsorption amount is outside a target range of the ammonia adsorption amount, addition of an ammonia precursor or ammonia using an adding valve is controlled such that the specific ammonia adsorption amount returns to the target range.

A method and a unit for operating or for the operation of a fuel metering system of an internal combustion engine, in particular in a motor vehicle, and it being provided, in particular, that at least one operating variable of the internal combustion engine is detected, a dynamic operating state of the internal combustion engine is detected based on the at least one detected operating variable, and a dynamic correction to the fuel metering system of the internal combustion engine is carried out for a detected dynamic operating state of the internal combustion engine, taking into account the efficiency of an NOx exhaust gas aftertreatment system.

A method for cleaning an SCR system, wherein reducing agent is supplied to an exhaust flow upstream of an SCR catalyst (260), NO.sub.X contents of the exhaust flow are determined upstream and downstream of the SCR catalyst (260) and reducing agent crystals are removed by a high-temperature procedure. The steps are determining (s430) a ratio (K1) between NO.sub.X contents downstream and upstream of the SCR catalyst (260), raising the temperature (s440) of the exhaust flow to vaporize reducing agent crystals with a view to cleaning, determining (s450) a ratio (Kn) between respective NO.sub.X contents determined downstream and upstream of the SCR catalyst (260) at a temperature (T2) of the SCR catalyst (260) at which reducing agent crystals vaporize, comparing (s460) the ratios (K1, Kn) and using this comparison as a basis for deciding whether reducing agent crystals have been removed to an intended extent. Also a computer program product containing program code (P) for a computer (200; 210) for implementing the method according to the invention. The invention relates also to a device and a motor vehicle equipped with the device.

An internal combustion engine (1), with an engine regulating device (3) and an exhaust gas aftertreament device (16) with an SCR catalytic converter (4) for the reduction of at least one NO.sub.x component, and with a catalytic converter regulating device (6), wherein the engine regulating device (3) is prescribed a target value for an NO.sub.x mean value of the NO.sub.x component of the exhaust gases, which mean value results at an outlet point (7) of the exhaust gas aftertreatment device (16) in relation to a predefinable time period, and the engine regulating device (3) is configured at least in one operating mode to continuously calculate an NO.sub.x reference value for the catalytic converter regulating device (6) with consideration of No.sub.x components which have already been emitted and the predefined target value, which reference value is selected in such a way that the predefined target value results at the outlet point of the exhaust gas aftertreatment device (16) at the end of the predefinable time period when the calculated NO.sub.x reference value of the catalytic converter regulating device (6) is fed as NO.sub.x setpoint value to the regulating means.